MicroTherm Principles | Savings | How it Works | Applications | Features

MICROTherm is a microprocessor-based energy-saving device for hot water and some steam boilers that constantly monitors total demand on the boiler and proportionately adjusts the burner's cycles for optimum efficiency.

MICROTherm is a retrofit device that works with either gas- or oil-fired boilers and does not rely on troublesome outdoor temperature sensors.

MICROTherm reduces fuel consumption 10 - 20% and can pay for itself in the first year of operation.

MICROTherm works without lowering thermostats, and is fully compatible with any existing set-back or other energy-saving boiler control system.

MICROTherm reduces the number of burner ignitions and therefore extends the life of heating systems. Fewer ignitions produce less soot and exhaust, resulting in cleaner operation and improved air quality.

Principles

The success of MICROTherm is based on three concepts:

First, all boilers are inherently oversized.
According to ASHRAE guidelines, boilers are sized to accomodate the coldest days (5% of a year). During these periods of maximum demand, the burner is constantly on and the boiler is operating at its maximum capacity. At all other times, the burner cycles on and off maintaining temperature or pressure in the boiler. It is during these periods of lesser demand, perhaps 95% of the year, that MICROTherm saves energy.

Second, the length of the burner's off-cycle is the best measure of total heating demand or load.
In other words, the load is directly related to the time it takes for water (or steam) in the boiler to drop from its high-limit temperature (or pressure) to its low-limit or call setting. When demand is high, these off-cycles are short and the on-cycles are longer. When demand is lower, off-cycles are longer and on-cycles are reduced.

Measuring heating demand in this way accounts for all factors affecting a building's heating requirements. These factors include occupancy rates, wind chill, solar gain, insulation effectiveness, type of construction, thermostat settings, outdoor temperature, and many others. MICROTherm operates by constantly monitoring the off-cycles and adjusting their duration, therefore accounting for all factors. Most other boiler controls rely primarily on outdoor temperature as a measure of demand, and hence are of limited effectiveness.

Third, heat transfer from the burner to the boiler water is most effective after the boiler vessel has reached its highest temperature.

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